If you're getting a pre-buit PC u are already losing around 20-30% of what you could get cause companies take a percentage just for building it. It's really not difficult, you can find many tutorials on the internet that shows u step by step everything you need to do.
Edit: also about the monitor, I'd recommend going with AOC, they're great for the price, probably the best choice if you want to spend on PC as much as possible.
What everyone else said. Building a PC is super easy. I bought a pre-made one, and over the years have completely rebuilt it, case and all. If you mean you physically can't build it, this is a more than decent PC I found. The only thing is that this runs an AMD CPU, which means it's not packing as hard of a punch as Intel does. But with your budget, you weren't going to get absolute top of the line anyways. Close though. this leaves ~$400 to get a monitor/monitors and possibly keep some of your money afterwards. I would still recommend Mongius' partpicker list however.
All it takes is one bad day to reduce the sanest man alive to lunacy. That’'s how far the world is from where I am. Just one bad day.
When I build my new PC 3-4 years ago I was still completely new to computers at the time and never touched inside of a computer before, but couple of tutorial videos were more than enough to teach me everything that I needed. So yeah I hope it shows how easy it is and you shouldn't be afraid to try it, cause you will definitely save money and also learn a lot about your PC in process of building.
In case you chose to build it yourself, here are videos that you might find helpful:
Some things you should consider before buying the parts:
The build itself (most up to date and easiest to follow imo):
Also if you are looking to save money, don't buy everything at one sweep (this counts no matter if you chose to buy parts or a pre-built PC) because there are many discounts on computer parts all the time, so i'd suggest looking around different websites/different parts and buy them in a time span of 2-4 weeks. Trust me, that way you will save some money for sure.